不能从kissfft获得图像的2d-fft入侵

Question

我正在正确地获得图像的2d-fft，但不能从同一图像的2d-fft中获得的逆。

           What are the proper calls for getting inverse from the 2d-fft of that same image ???

// for 2d-fft. This I am getting properly
kiss_fftnd_cfg st = kiss_fftnd_alloc(dims, ndims, 0, 0, 0);
kiss_fftnd(st,(kiss_fft_cpx *)fftbuf,(kiss_fft_cpx *)fftoutbuf);

// for inverse. By using this I am getting the wrong values.
kiss_fftndr_cfg st2 = kiss_fftndr_alloc(dims, ndims, 1, 0, 0);
kiss_fftndri(st2, (kiss_fft_cpx *)fftoutbuf, (kiss_fft_scalar *)obuf);

// even I have tried this. By using this I am getting the wrong values.
kiss_fftr_cfg st3 = kiss_fftr_alloc( (rows * cols) , 1, 0, 0);
kiss_fftri( st3 , (kiss_fft_cpx *)fftoutbuf ,(kiss_fft_scalar *)rbuf);

Answer 1

你正在混合复杂的和真实的FFT。

正向/反向行为由*alloc函数的第三个参数inverse_fft控制(即复kiss_fftnd_alloc和实kiss_fftndr_alloc )。